Power transmission and conveyor chain has been used for more than two thousand years. Chain was used with lift buckets in the Third Century B.C. Leonardo da Vinci's drawings depict chains not unlike the present power and conveyor chains.
Power and conveyor chains have used standard pitches and widths and standard sizes of components, as described in American Chain Association manuals and in Chains for Power Transmission and Material Handling Design and Applications Handbook, published by the American Chain Association and edited by L. L. Faulkner and S. B. Menkes, Marcel Dekker, Inc., New York, 1982.
It is well known that, as chain wears, the chain length is extended. When chain fails, it either fails by shear in the pins or links or by tensile stress in the links. Either deformation, extension or parting may cause chain failure and end usefulness of a particular chain or its parts.
Since one common chain failure is found in link fatigue or creep or extension, it has been heretofore thought important to keep the links strong by reducing the holes formed in the links to receive pins or bushings.
This mental bent for strengthening chains and preventing failures and extending use is reflected in the standards of chain and component sizes for power transmission and conveyor chains, indicated in the American Chain Association handbook.
Extending chain life and preventing premature failure have been the objects of engineers and chain manufacturers for a long time.
One patent which describes particular chain constructions in seeking an optimum of life and strength is U.S. Pat. No. 3,054,300. Another patent which seeks to optimize strength and weight is an older U.S. Pat. No. 2,182,443.
Present chain used today is manufactured according to standards adopted by the American National Standards Institute and developed, revised and updated by the American Chain Association.